During this study septic conditions developed in the oxidation pond in the spring when the ice melted. Shortly after this study ended septic conditions resulted which required the addition of sodium nitrate. The location of the oxidation pond in a high value residential area makes odor nuisances a sensitive problem for the developer. The organic concentration in the influent raw sewage ranged from 160 to 270 mg/l of BOD with an average of 230 mg/l. The BOD data are given in Table 4,. A single 24 -- hr composite sample had a BOD of 260 mg/l, indicating a typical domestic sewage. The daily sewage volume to the oxidation pond averaged 147000 gpd, giving a retention period of 42 days. The organic loading on the pond was slightly under 60 lb BOD/day/acre.

The effluent BOD averaged 34 mg/l, a little lower than that of the study at Fayette indicated for a loading of 60 lb BOD/day/acre. The BOD of the effluent ranged from a minimum of 13 to a maximum of 47 mg/l. Microscopic examination of the effluent showed that minimum BOD occurred when the algae began to decrease with cold weather. When the algae began to build up again, the effluent BOD rose. During the two weeks when the algae disappeared from the effluent BOD's in the effluent were 18 and 16 mg/l.